In semiconductor integrated circuit (IC) manufacturing, wafers are tested during manufacturing and prior to shipment to ensure proper operation. Wafer testing is a testing technique where a temporary electrical connection is established between automatic test equipment (ATE) and dies formed on the wafer to demonstrate proper performance of the ICs.
Along with complexity improvement of circuit designs, rapid development of semiconductor fabrication processes, and demand for circuit performance, ICs have been developed with a three-dimensional (3D) structure to increase circuit performance. There are many different processes required to manufacture a 3DIC including grinding, etching, milling, various deposition techniques, and the like. These processes can generate charges on the manufactured devices. Due to the increasing requirements for more test patterns for a single die, the test time and test cost are dramatically increased.